My Cat Has Diarrhea

CatChannel veterinary expert Arnold Plotnick, DVM, discusses various tests and treatments for the ailment.

By Arnold Plotnick, DVM | Posted: October 16, 2009, 3 a.m. EDT

Printer Friendly

Q: I have a 12-year-old Cornish Rex and he is suffering from diarrhea (for over three weeks now).  My vet did extensive blood work and found no cause. She had me give my cat 1/8 tablet of pro pectalin and 1/4 tablet of Metronidazole every 12 hours and changed his food to Hill's Science Diet A/D. It has been three weeks and no result. My vet is out of ideas.  

A: There are many reasons for a cat to have diarrhea. I suspect your vet has probably performed the common blood tests that you’d want to do for a 12-year-old cat, to rule out common metabolic causes for diarrhea, such as hyperthyroidism.  Your vet may want to perform a blood test called a TLI test, to rule out pancreatic insufficiency (underproduction of pancreatic digestive enzymes) and a PLI test, to rule out pancreatitis (inflammation of the pancreas).  A test that measures the vitamin B12 and folate levels would also be useful, as it would provide information as to whether your cat might have small intestinal bacterial overgrowth.
Intestinal parasitism, while less likely in a 12-year-old indoor cat, should be ruled out by running a fecal examination.  The feces should also be cultured for Salmonella, Campylobacter and other common bacterial intestinal pathogens. If all of these tests do not yield a diagnosis, you can attempt symptomatic treatment.

First, you should rule out food hypersensitivity by feeding a bland, highly digestible diet, such as Hill’s I/D or Iams Low Residue Formula. Hill’s A/D is very nutritious, but may be perhaps a bit rich for cats with diarrhea. If there’s no response to these diets, you can try treating for presumptive food allergy by feeding a hypoallergenic diet. This is a diet that contains a protein source that the cat has never encountered before. Hill’s makes prescription diets in which the protein source is either venison or duck. If this doesn’t resolve the problem, you can try treating empirically, with an antibiotic with efficacy for intestinal disorders, such as Metronidazole (which apparently is not working for you), or Tylosin.

Ultimately, if you cannot control the diarrhea symptomatically, your cat may have to undergo some advanced diagnostics, such as gastrointestinal endoscopy, to rule out disorders such as inflammatory bowel disease or gastrointestinal lymphoma. 


Printer Friendly

 Give us your opinion on
My Cat Has Diarrhea

Submit a Comment   Join Club
Earn 1,000 points! What's this?
Reader Comments

CatChannel Editor    Irvine, CA

12/18/2013 10:00:09 AM

Brian -- Take your cat to the vet. It is clearly ill and the vet is the only one who could help.

brian    troutdale, OR

12/17/2013 9:38:27 PM

my 1 year old cat has fallen sick since we have put up x-mas tree. he has diarrhea and get sick every hour or so. this seems to have started since he had hid distemper and rabies shot on Saturday and the x-mas tree on Sunday. for 1 year the cat has never missed the cat box. today he has urinated on the couch,vaumented several times, and defecated 4-5 times today. what should I do????

CatChannelEditor    Irvine, CA

9/4/2012 1:08:16 PM

Diana -- I'm sorry your cat is suffering from this long bout of illness. Your vet is the best person to help get your cat back on track. A weight loss this significant can only be helped by proper diagnosis and treatment. Did you tell your vet that you were discontinuing the antibiotic? These are always diagnosed for a specific amount of time, and stopping them early also stops treatment. With the diarrhea being such a problem, your vet must be alerted so he/she can help this side effect.

Diana    Mesa, AZ

9/1/2012 3:47:01 PM

The information was very informative and I will be trying these ideas. My cat has been sick for over 4 weeks now, and the medications prescribed have not resolved his problem He has deteriorated to an extreme, going from 26 lbs to now 5 lbs.
He is only 10 years old, and I do not want to see him leave this world.
He had lab work completed and the Vet found he had an infection in his system, aldo his pancreas was inflamed. He was given a shot of (corsevia) but it did not help, he was then given an oral antibiotic that made his diarreha worse, I suspended it after 2 doses.
If there is anything else you could recommend I would be forever greatful.

Thank you,


View Current Comments

Top Products